The overall Arctic sea ice extent has shrunk by 40 percent in 10 years, TASS news agency cited Valery Karklin, leading researcher at the Arctic and Antarctic Research Institute (AARI), as saying.

"On average, over the summer months (July, August and September) of 2005-2015, the total ice cover in the Arctic seas, including the Kara, Laptev, East Siberian and Chukchi seas, has declined by 40 percent or 547,000 square kilometers," Karklin said. He added that the numbers for 2016 will be released later.

He said ice conditions in the Arctic seas had formed over those years in the context of lasting climate warming. "Over the 10-year period, summer ice conditions throughout the Arctic seas that the Northern Sea Route crosses were mild. They were characterized by early ice melting, intensive sea ice clearing and reduced ice thickness," Karklin explained.

The researcher added that based on information from polar stations, throughout the winter period of 2005-2015 the thickness of fast (immovable) ice shrank by 10-40 centimeters to about 20 centimeters or 15 percent of the perennial norm.

"In summer, the thickness of drifting ice in the Arctic seas declines by 120-140 centimeters due to the melting, as compared to the average longstanding norm of 80-100 centimeters. As we can see, the ice has got 40 centimeters thinner. Mild ice conditions in the Arctic seas are favorable for navigation due to a prolonged period of icebreaker-free navigation (there is no need for icebreakers to escort vessels through heavy ice). The situation also helps to reduce the number of accidents," Karklin pointed out.

He also said mild ice conditions are favorable for conducting geological exploration on the Arctic shelf and operating facilities for raw hydrocarbons extraction and transportation.